Levsin SL

CLINICAL PHARMACOLOGY

Levsin®/SL (hyoscyamine sulfate tablets) inhibits specifically the actions of acetylcholine on structures
innervated by postganglionic cholinergic nerves and on smooth muscles that respond
to acetylcholine but lack cholinergic innervation. These peripheral cholinergic
receptors are present in the autonomic effector cells of the smooth muscle,
cardiac muscle, the sinoatrial node, the atrioventricularnode, and the exocrine
glands. At therapeutic doses, it is completely devoid of any action on autonomic
ganglia. Levsin®/SL (hyoscyamine sulfate tablets) inhibits gastrointestinal propulsive motility and decreases
gastric acid secretion. Levsin®/SL (hyoscyamine sulfate tablets) also controls excessive pharyngeal, tracheal
and bronchial secretions.

Levsin®/SL (hyoscyamine sulfate tablets) is absorbed totally and completely by sublingual administration
as well as oral administration. Once absorbed, Levsin®/SL (hyoscyamine sulfate tablets) disappears rapidly
from the blood and is distributed throughout the entire body. The half-life
of Levsin®/SL (hyoscyamine sulfate tablets) is 2 to 3½ hours. Levsin®/SL (hyoscyamine sulfate tablets) is partly hydrolyzed to tropic
acid and tropine but the majority of the drug is excreted in the urine unchanged
within the first 12 hours. Only traces of this drug are found in breast milk.
Levsin®/SL (hyoscyamine sulfate tablets) passes the blood brain barrier and the placental barrier. The
tablets can be taken orally with the same pharmacological effects occurring;
however, the effects may not occur as rapidly as with sublingual administration.

Last reviewed on RxList: 3/13/2009
This monograph has been modified to include the generic and brand name in many instances.